 |
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| Aquifer |
|
A
natural water-bearing geological
formation (e.g. sand, gravel,
sandstone) that is found below
the surface of the earth. |
|
|
|
| Commercial
Water Use |
|
Water
used for motels, hotels, restaurants,
office buildings, and other commercial
factilities and institutions.
Water for commercial use comes
both from public-supplied sources,
such as a county water department,
and self-supplied sources, such
as local wells. |
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|
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| Contaminant |
|
Any
undesirable physical, chemical,
or microbiological substance or
matter in a given water source
or supply. Anything in water which
is not H2O may be considered a
contaminant. |
|
|
|
| Domestic
Water Use |
|
Water
used for household purposes, such
as drinking, food preparation,
bathing, washing clothes, dishes,
and dogs, flushing toilets, and
watering lawns and gardens. The
main supply is a public-supply
facility, and the remainder from
wells. |
|
|
|
| Drinking-Water
Standard or Guideline |
|
A
threshold concentration for a
constituent or compound in a public
drinking-water supply, designed
to protect human health. As defined
here, standards are U.S. Environmental
Protection Agency regulations
that specify the maximum contamination
levels for public water systems
required to protect the public
welfare; guidelines have no regulatory
status and are issued in an advisory
capacity. |
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| Ground
Water |
|
(1)
Water that flows or seeps downward
and saturates soil or rock, supplying
springs and wells. The upper surface
of the saturate zone is called
the water table. (2) Water stored
underground in rock crevices and
in the pores of geologic materials
that make up the Earth’s
crust. |
|
|
|
| Industrial
Water Use |
|
Water
used for industrial purposes in
such industries as steel, chemical,
paper, and petroleum refining.
Nationally, water for industrial
uses comes mainly (80%) from self-supplied
sources, such as local wells or
withdrawal points in a river,
but some water comes from public-supplied
sources, such as the county/city
water department. |
|
|
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| Inorganic
Contaminants |
|
Mineral-based
compounds such as metals, nitrates,
and asbestos; naturally occurring
in some water, but can also enter
water through human activities. |
|
|
|
| Leaching |
|
The
process by which soluble materials
in the soil, such as salts, nutrients,
pesticide chemicals or contaminants,
are washed into a lower layer
of soil or are dissolved and carried
away by water. |
|
|
|
| Livestock
Water Use |
|
Water
used for livestock watering, feed
lots, dairy operations, fish farming,
and other on-farm needs. |
|
|
|
| Maximum
Contaminant Level (MCL) |
|
The
designation given by the U.S.
Environmental Protection Agency
(EPA) to water-quality standards
promulgated under the Safe Drinking
Water Act. The MCL is the greatest
amount of a contaminant that can
be present in drinking water without
causing a risk to human health. |
|
|
|
| Maximum
Contaminant Level Goal (MCLG)
|
|
The
level of a contaminant at which
there would be no risk to human
health (not a legally enforceable
standard). |
|
|
|
| Milligram
(mg) |
|
One-thousandth
of a gram. |
|
|
|
| Milligrams
per Liter (mg/l) |
|
A
unit of the concentration of a
constituent in water or wastewater.
It represents 0.001 gram of a
constituent in 1 liter of water.
It is approximately equal to one
part per million (PPM). |
|
|
|
| Million
Gallons per Day (Mgd |
|
A
rate of flow of water equal to
133,680.45 cubic feet per day,
or 1.5472 cubic feet per second,
or 3.0689 acre-feet per day. A
flow of one million gallons per
day for one year equals 1,120
acre-feet (365 million gallons). |
|
|
|
| National
Water-Quality Assessment (NAWQA)
|
|
The
long term USGS program, begun
in 1991, to assess the occurrence
and distribution of water-quality
conditions nationwide. |
|
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|
| Organic
Contaminants |
|
Carbon-based
chemicals, such as solvents and
pesticides, which enter water
through cropland runoff or discharge
from factories |
|
|
|
| Potable
Water |
|
A
water supply which meets USEPA
and/or state water quality standards
and that is considered safe and
fit for human consumption. |
|
|
|
| PPB |
|
A
measure of proportion by weight
which is equivalent to one unit
of weight of solute (dissolved
substance) per billion unit weights
of the solution. This measurement
is often used as a measure of
concentration when analyzing water
for contaminants. Since one liter
of water weighs one billion micrograms,
one ppb is the equivalent of one
microgram per liter when used
in water analysis |
|
|
|
| Reverse
Osmosis |
|
A
water treatment process that removes
undesirable materials from water
by using pressure to force the
water molecules through a semi-permeable
membrane. This process is called
“reverse” osmosis because
the pressure forces the water
to flow in the reverse direction
(from the concentrated solution
to the dilute solution) to the
flow direction (from the dilute
to the concentrated) in the process
of nature osmosis |
|
|
|
| USEPA |
|
United
States Environmental Protection
Agency |
|
|
|
| Wastewater |
|
Water
that has been used in homes, industries,
and businesses that is not for
reuse unless it is treated. |
|
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|
| Water
Quality |
|
A
term used to describe the chemical,
physical, and biological characteristics
of water, usually in respect to
its suitability for a particular
purpose. |
|
|
|
| WQA |
|
Water
Quality Association |
